Unfortunately, Decimal fields have several known issues that limit their usefulness and they should be avoided whenever possible.
The main issue is with sorting decimal fields in descending order. Zeros and negative values are the sorted incorrectly, as demonstrated in the screenshot below:

In the above example, negative values appear before positive values, and 0 appears at the end of the list. This issue is documented in
Microsoft's KB article 837148.

In addition to the sorting problem, there are several other problems with Decimal types, including: